MCR-1

The mobilized colistin resistance (mcr-1) gene confers plasmid-mediated resistance to colistin, one of a number of last-resort antibiotics for treating gram negative infections. mcr-1 is capable of horizontal transfer between different strains of a bacterial species and after discovery in November 2015 in E. coli (strain SHP45) from a pig in China it has been found in Escherichia coli, Salmonella enterica, Klebsiella pneumonia, Enterobacter aerogenes, and Enterobacter cloacae.As of 2017^[update] it has been detected in more than 30 countries on 5 continents in less than a year.

The "mobilized colistin resistance"(mcr-1) gene confers plasmid-mediated resistance to colistin, a polymyxin and one of a number of last-resort antibiotics for treating infections.

mcr-1 is the first polymyxin resistance gene known to be capable of horizontal transfer between different strains of a bacterial species. The gene has been found in at least five species of bacteria: Escherichia coli, Salmonella enterica, Klebsiella pneumonia, Enterobacter aerogenes, and Enterobacter cloacae. It has been experimentally transferred in the lab from E. coli to Pseudomonas aeruginosa.